A recent study published in JAMA Internal Medicine indicates that vitamin K2 (menaquinone 7) supplementation can significantly alleviate nocturnal leg cramps (NLCs) in older adults. The multicenter, double-blind, placebo-controlled trial conducted in China offers a potential new approach to managing this common and distressing condition.
The study, led by researchers from the Third People's Hospital of Chengdu, enrolled 199 participants aged 65 years and older (mean age 72.3) who experienced two or more NLC episodes during a two-week screening period. Participants were randomized 1:1 to receive either 180 μg of vitamin K2 or a placebo daily for eight weeks.
The primary outcome measured was the mean number of NLCs per week. Secondary outcomes included the duration and severity of muscle cramps, assessed using an analog scale from 1 to 10.
Significant Reduction in Cramp Frequency and Severity
At baseline, both groups reported a similar frequency of NLCs, with 2.60 cramps per week in the vitamin K2 group and 2.71 in the placebo group. However, during the eight-week intervention, the vitamin K2 group experienced a significant reduction in the mean weekly frequency of cramps to 0.96, compared to 3.63 in the placebo group. This represents a statistically significant difference of 2.67 fewer cramps per week (p<0.001).
Furthermore, the vitamin K2 group showed a notable reduction in NLC severity, with a mean decrease of 2.55 points compared to 1.24 points in the placebo group. The duration of NLCs also decreased by a mean of 0.90 minutes in the vitamin K2 group, compared to 0.32 minutes in the placebo group.
Safety and Future Directions
Notably, no adverse events related to vitamin K2 use were identified during the trial. This suggests that vitamin K2 supplementation may be a safe and well-tolerated option for managing NLCs in older adults.
The researchers concluded that vitamin K2 supplementation significantly reduces the frequency, intensity, and duration of nocturnal leg cramps in older adults without causing adverse events. They recommend future clinical trials to confirm these findings and to investigate the impact of vitamin K2 on the quality of life and sleep in patients with frequent NLCs. Approximately 50% to 60% of adults experience NLCs in their lifetime, with about 20% encountering significant distress and insomnia that lead them to seek medical intervention. There are currently limited medical treatments available without substantial side effects, highlighting the need for alternative therapies.
